DNER-IgG screening of 3290 cerebral spinal fluid samples: Two autoimmune cerebellar ataxia cases without tumors in long-term follow-up

Background

This study aimed to retrospectively report the findings of delta/notch-like epidermal growth factor-related receptor (DNER)-immunoglobin G (IgG) in cerebral spinal fluid (CSF) in two cases with cerebellar ataxia.

Methods

: CSF samples were collected from 3290 patients with possible autoimmune encephalitis. The immunofluorescence pattern was reviewed using a tissue-based assay.

Results

: An immunofluorescence pattern with a specific IgG-binding pattern in the cytoplasm of cerebellar Purkinje cells, as well as a fine-dotted pattern in the molecular layer, was found in two samples (0.06%, 2/3290), each from one patient. DNER-IgG was confirmed by cell-based assays. Both of the patients were male and did not have tumors. This suggests that cerebellar ataxia was the main manifestation. Brain magnetic resonance imaging showed non-specific lesions in both patients. One patient responded well to steroid treatment, but the other patient demonstrated a weak response to treatment. During the two-year follow-up period, both patients were stable, and no tumors developed in either patient.

Conclusion

The DNER-IgG antibody is rarely found in patients with possible autoimmune encephalitis, and therefore it is not necessarily associated with tumors.